Canadian Prime Minister Justin Trudeau on Sunday slammed the tariffs imposed by the Trump administration on steel and aluminium as "insulting and unacceptable" and said he would retaliate by placing similar penalties on US goods.

Beginning this month, US President Donald Trump has imposed a 25% tariff on import of steel from Canada and another 15% on aluminium using the "national security interest" provisions of the existing American laws.

"We're putting the same kinds of tariffs exactly on steel and aluminium coming from the United States into Canada to be directly reciprocal. But we're also putting a number of tariffs on consumer goods, finished products for which Canadians have easy alternatives," Trudeau told NBC News in an interview during a talk show.

"One of the things that I have to admit I'm having a lot of trouble getting around is the idea that this entire thing is coming about because the president and the administration have decided that Canada and Canadian steel and aluminium is a national security threat to the United States," he said.